Method for matching transmitters and receiver

ABSTRACT

A receiver is matched with two transmitters ( 8, 10, 12 ); the receiver ( 4 ) supplies a first transmitter ( 8 ) with an address and simultaneously stores the supplied address. The first transmitter stores the address supplied by the receiver. The receiver then supplies to a second transmitter ( 10 ) an address different from the address supplied to the first transmitter; the receiver simultaneously stores the supplied address. The second transmitter stores the address supplied by the receiver. The supply of different addresses for different transmitters enables to improve security by using between each transmitter and the receiver revolving code methods.

BACKGROUND OF THE INVENTION

The invention relates to the field of transmitters and receivers, and inparticular transmitters and receivers of home automation systems.

Such systems are used for motorized products or automatic devices forclosing or for solar protection in buildings or for the control oflighting or other units. Typically, one or more transmitters areprovided; each device to be controlled—rolling shutter, blind, lightingunit, etc—is associated with a receiver; it is also possible forprovision to be made for several devices to be controlled by a samereceiver. The radio transmitters and receivers use the same transmissionfrequency, or predetermined frequencies. For these devices, and inparticular for motorized products or automatic devices for closing orfor solar protection in buildings, logistic reasons most oftennecessitate that the pairing is not performed during manufacture, butrather on the worksite, after installation of the products.

A first known solution consists in allocating each transmitter with itsown identifier which, during a learning procedure, is directly orindirectly stored in the receiver. Thus, in U.S. Pat. No. 4,750,118, therespective identifiers of a plurality of transmitters can be recorded ina memory located in the receiver. During operational functioning, thelatter validates a received command only after having observed that thiscommand is coming from a transmitter whose identifier has been recordedpreviously.

Similarly, but in a more sophisticated manner, U.S. Pat. No. 6,049,289provides for the recording in the receiver of both an identificationnumber and a secret key, transmitted by the transmitter during alearning phase of the receiver.

In both of the cases mentioned relating to this first principle, eachtransmitter is therefore characterized only by a single identifier. Thisidentifier corresponds to a factory code.

Thus, according to this first principle, during the successive pairingsof the receiver with the plurality of transmitters intended to controlit, a table of authorised identifiers is progressively constructed inthe receiver.

Another known solution consists in allocating the receiver with a uniqueidentifier. It is therefore this identifier that is communicated, duringa learning operation to each one of the transmitters authorized tooperate the equipment. Thus U.S. Pat. No. 4,529,980 discloses a systemin which the identifier of the receiver is transmitted to thetransmitter via an optical link. The transmitter optionally containsseveral memories, in order to learn as many identifiers as there aredifferent devices to control, and therefore as there are receivers. Thequoted patent describes, for example, a remote control unit having fourdifferent channels.

U.S. Pat. No. 5,148,159 provides a variant of the above method whereinthe link between the receiver and the transmitter is produced by aserial transmission of the asynchronous type at the moment of eachpairing.

In both cases mentioned with respect to this second principle, eachreceiver is therefore characterized only by one single identifier. Thisidentifier corresponds to a factory code, or even to a code establishedin a random manner according to a special code allocation procedurewhich can be activated by the owner of the installation.

It has furthermore been proposed to change the code transmitted by atransmitter to the receiver at each transmission; in the event of aclandestine recording of the signal transmitted by radio from thetransmitter to the receiver, this technique prevents the transmission ofthe recorded signal from being able to control the receiver. Such asolution is described in U.S. Pat. No. 6,089,289: in this document, boththe transmitter and the receiver are provided with a memory containing asynchronisation value; this synchronisation value is incremented in thetransmitter at each transmission of a command to the receiver. Thesynchronisation value is incremented in the receiver each time a commandcoming from the transmitter is received. A problem associated with thistype of solution is that the transmitter can be actuated outside of thereceiver's range such that the synchronisation values in the transmitterand the receiver differ. The solution proposed in U.S. Pat. No.6,089,289 consists in providing in the receiver a range of acceptablesynchronisation values which contains not only the expected nextsynchronisation value but also the next 15 expected values. In thisdocument there is also provided a self-synchronisation procedure in thecase where the transmitter is actuated out of the receiver's range morethan 15 times.

SUMMARY OF THE INVENTION

There is therefore a need for a reliable, simple and secure method oftransmission of commands from a plurality of transmitters to a receiverwhich applies to paired transmitters and receivers.

In one embodiment, the invention therefore provides a method of pairinga receiver with at least two transmitters and comprising the steps of:

-   (a) the supply of an address by the receiver to a first transmitter,    and storage of the supplied address by the receiver;-   (b) storage of the address by the first transmitter;-   (c) supply by the receiver to a second transmitter of an address    different from the address supplied to the first transmitter, and    storage by the receiver of the supplied address;-   (d) storage by the second transmitter of the address supplied by the    receiver; each transmitter being able to transmit to the receiver a    command, that is a function of the stored address, the receiver    executing the command only if the address of which it is a function    is an address stored in the receiver.

Preferably, the supply step comprises the generation of the address by apseudo-random generator.

It is also possible to provide for the method to comprise, for atransmitter, the modification according to a predetermined algorithm ofthe stored address or of a part of the latter after the sending of acommand to the receiver. It is therefore preferable for the method tocomprise, for the receiver, the modification according to apredetermined algorithm of the stored address, or of a part of thelatter, for a transmitter after receipt of a command from thattransmitter.

It is also possible to provide a step of deletion by the receiver of theaddress supplied to a transmitter.

In another embodiment, the invention provides a non-paired receiver,comprising command receiving means, a table containing at least twoseparate addresses and a circuit capable of extracting an address from acommand received by the receiving means and of comparing an extractedaddress and the addresses in the table.

Advantageously, the receiver comprises a means of transmitting anaddress from the table. The table can contain, for an address, anassociated rolling code value. It can also have, for an address, a fieldrepresenting the transmission of that address.

Finally, the invention provides an installation comprising such areceiver and at least two transmitters.

Other characteristics and advantages of the invention will appear onreading the following description, given by way of example and withreference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of an installation according to theinvention;

FIG. 2 is a block diagram of the logic structure of a receiver accordingto the invention;

FIG. 3 is a block diagram of the logic structure of a transmitteraccording to the invention;

FIG. 4 is a flowchart of a method used in the receiver;

FIG. 5 is a flowchart of the method used in the transmitter.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a diagrammatic view of an installation in a first exampleembodiment of the invention. The installation comprises an operatingunit 2, referenced by the letter “O” in the figure. This operating unitcan, for example, roll up or unroll blinds, rolling shutters or a garagedoor, actuate a lighting unit, open a door, start or stop an alarm, etc.The operating unit is connected to a receiver, referenced by the letter“R” in the figure. The receiver has an antenna 6 which allows it toreceive commands transmitted by radio link from a transmitter. The radiotransmission of commands from a transmitter to a receiver is known perse and is not described in greater detail here. FIG. 1 also shows aplurality of transmitters 8, 10, 12. Each transmitter is designed totransmit one or more commands by radio to the receiver 4 and, for thispurpose, has an antenna which is not shown. Typically, a transmitter, inthe case of controlling a rolling shutter, can transmit commands toraise, lower or stop the shutter; other commands can be provided, suchas the placing of the shutter in pre-programmed positions, shutterprogramming commands, etc. The transmitter therefore has one or moredevices allowing the user to enter a command; in the simplest case thesecan be one or more control buttons.

Furthermore, the receiver is designed to also transmit signals to thetransmitters; as explained below, the transmission of signals from thereceiver to the transmitter allows the pairing of the transmitters withthe receiver. Because of this, this transmission is not used during thenormal functioning of the installation and can have functionalcharacteristics—transmission range, transmission capacity, etc.—that arelower than for the transmission in the direction from the transmitter tothe receiver. It is possible to provide various transmission channelsfrom the receiver to a transmitter; radio is used in a simpleconfiguration, the transmitter and the receiver then constituting a“transceiver”, that is to say a transmitter-receiver; this solution hasthe advantage of simplicity, but is rather costly. It is possible toprovide transmission via an optical channel by providing the receiverwith an infrared diode 14 and a transmitter 8, 10 or 12 with acorresponding sensor 16, 18, 20; it is also possible to providetransmission by electrical signals by providing the receiver and thetransmitter with contacts that can be connected to each other. Whicheversystem is used, the receiver can transmit signals and programmingcommands to the transmitter.

The problem of the invention is to pair the transmitter or transmitterswith the receiver, in other words to ensure that the commandstransmitted by certain transmitters make it possible to actuate theoperating unit by the intermediary of the receiver—whilst thetransmission of commands by other transmitters has no effect.

For this purpose, the invention provides that the receiver supplies eachof the transmitters that must be paired with it with an identifier thatis unique to the transmitter. This identifier is furthermore stored bythe receiver. This identifier is subsequently used by the transmitter toidentify the commands transmitted to the receiver; the receiver can thusdetermine the origin of the commands that it receives and execute acommand only if it comes from a transmitter that is paired with it. Themethod is described in greater detail below with reference to FIG. 4.

As the receiver contains an identifier for each of the transmitters, itis possible to implement, independently for each of the identifiers,protection methods of the rolling code or other type. The inventiontherefore overcomes the disadvantage of the devices described in U.S.Pat. No. 4,529,980 or U.S. Pat. No. 5,148,159, which cannot support theso-called rolling code transmission security means.

For purposes of simplification, the register of the transmittercontaining the rolling code to be used for the next transmission isdenoted by “RCT” and the register of the receiver containing theexpected value for the next rolling code is denoted by “RCR”. In thecase of a plurality of authorized transmitters, even if the rate of useis not the same from one user to another, each transmitter will have itsregister RCT evolving in way that is independent from the othertransmitters: the receiver is capable of identifying each transmitter Tiand can therefore, independently from the other transmitters, update theregister RCRi corresponding to that transmitter. The use of differentidentifiers or addresses for each transmitter therefore makes itpossible to implement security by rolling code, even if the respectiverates of use of the transmitters are different.

The invention therefore makes it possible for remote control systemsaccording to the second principle to have at least the same level ofsecurity as the systems according to the first principle.

Furthermore, the presence of an identifier for each transmitter allowssimple and reliable management of the different transmitters; in thecase of loss or theft of a transmitter, it suffices to delete theidentifier allocated to the lost or stolen transmitter from thereceiver's memory for the command transmitted by that transmitter to beno longer considered by the receiver as a valid command.

FIG. 2 is a block diagram of the logic structure of a receiver accordingto the invention; as explained above, the receiver 4 has an antenna 6and is connected to an operating unit 2. The receiver comprises areception stage 24 which, in the proposed example, is a radio-frequencyreception stage receiving the signals picked up by the antenna 6. Italso has a means of transmission, in this example an infrared diode 14;as mentioned above, the transmission means allows a communication,preferably short-range, to the transmitter and which is used, inparticular, during a phase of pairing the transmitter with the receiver4.

The receiver 4 also contains a table or memory 26 containing the validaddresses for the control of the receiver. The receiver also contains ahardware or software device 28 for switching to the pairing or learningmode. When this device is activated, the receiver 4 switches intopairing mode. When it ceases to be activated, the module returns to theoperational mode. The device 28 is for example a button present on thereceiver, as shown in the figure, or it can be sensitive to a momentarybreak in the electrical power supply of the receiver. The device 28 canalso be sensitive to a particular command received by the antenna 6.

The operation of the different components of the receiver is controlledby a microprocessor 30 or by any other means carrying out suchfunctions.

When it is in the pairing mode, the receiver 4 transmits, using thetransmission means 14, the content of an address in the table that hasnot already been transmitted. This transmission can be managed accordingto any protocol adapted to the transmission channel used from thereceiver to the transmitter. Thus, on an infrared or optical link, it ispossible to use a serial transmission protocol. It is also possible touse a transmission protocol of the trial-and-error type: the transmitterto be paired transmits sequences of n bits (for example four bits). Eachtime a configuration corresponds to n specific bits of the address to betransmitted, the receiver 4 transmits a simple signal. The transmitter,which receives this signal, records the current configuration andreiterates the process, knowing that is it now relating to the followingn bits of the address. The algorithms of the transmitter and of thereceiver 4 are of course based on the same rule for breaking down andscanning the address in packets of n bits. This solution limits thetransmission from the receiver to the transmitter and can, in certaincases, be more advantageous by simplifying the link in the receiver totransmitter direction.

In normal operational mode, the receiver 4 receives, via the antenna 6,signals coming from transmitters. A transmitter intended to control theactuator controlled by the receiver 4 accompanies the addresstransmission frame which has been transmitted to it by the receiverduring the pairing phase. After reception, the receiver 4 checks that itis an address contained in the table 26; if this is the case, thereceiver decodes the rest of the frame and consequently controls theoperating unit.

FIG. 3 is a block diagram of the logic structure of a transmitteraccording to the invention. The transmitter 8 itself contains a remotetransmitter 34, for example a radio transmitter, with the associatedtransmission stage 36; it also contains, as explained above, a means ofreception 16 designed to receive the signal transmitted by the receiver4, preferably by a short-range link.

The transmitter also contains at least one memory location 38 allowingit to store in a durable manner the address that is transmitted to it bythe receiver 4 in the pairing phase, this being the address that it isauthorized to use for communications with this receiver.

The transmitter also contains a hardware or software device allowing itto switch into pairing mode. It can be a button 40, as shown in thefigure; it is also possible to program the transmitter such that isswitches into pairing mode on receipt of a pairing command from thereceiver 4; it is also possible to program a sequence of keys that isnot very probable in normal operation, which causes the transmitter toswitch into the pairing mode. In this pairing mode, the reception means16 is activated, and the data received from the receiver 4 is stored inthe durable memory 38. As for the receiver, a microprocessor 41 or anyother computing circuit which controls the functioning of the variouscomponents of the transmitter is provided.

FIG. 4 is a flowchart of a method used in the receiver; step 42represents the switching on of the receiver; in the first step 44, atest is performed to see if the receiver is in pairing mode; if this isthe case, the process moves on to step 46 and an address to betransmitted to the transmitter is chosen. As explained below, this stepcan, in the simplest embodiment, consist of choosing an address from thetable; it is also possible to generate the address and to store it inthe table. In the next step 48, the chosen address is transmitted to thetransmitter; this step can of course differ depending on the protocolused. The process then returns to step 44.

In step 44, if the receiver is not in pairing mode, the process moves onto step 50 in which the receiver waits for a command. When a command isreceived, the process moves on to step 52, in which the command isanalysed, if necessary with decoding, in order to extract the addressincluded in the command by the transmitter.

In step 54, the address used by the receiver is compared with theaddresses stored in the memory 26 of the receiver. If the address is nota valid address, the process returns again to step 50, waiting for acommand, or to step 44. On the other hand, if the address corresponds toan address stored in the memory 26 of the receiver, the process moves tostep 56; in this step the received command is executed by transmittingthe instruction corresponding to the command to the operating unit. Theprocess then moves to step 50, or to step 44. The choice of one or otherof these steps depends on the way in which the switching to pairing modeis controlled—in particular if this switching to pairing mode caninterrupt the operational functioning; in the example, it is implicitlyassumed that it is possible to enter the pairing mode only after theswitching on of the device. The process therefore moves to step 50 afterstep 54 or 56.

FIG. 5 is a flowchart of the method used in the transmitter. Step 60represents the switching on of the receiver; in the first step 62, atest is preformed to see if the receiver is in pairing mode; if this isthe case, the process moves to step 64 and waits for the receiver totransmit an address. In the next step 66, the received address is storedin the memory 38. The process then returns to step 62.

In step 62, if the transmitter is not in pairing mode, the process movesto step 68, in which the transmitter is waiting for an actuation by theuser. When the user presses the button or one of the buttons of thetransmitter, the process moves to step 70, in which the address is readfrom the memory and a command including the address is prepared. In step72, the prepared command is transmitted to the receiver. The processthen moves to step 68, waiting for a command, or to step 62. As above,the choice of one or other of these steps depends on the way in whichthe switching into pairing mode is controlled—in particular if thisswitching into pairing mode can interrupt the operational functioning.

The operational mode described above can be the subject of manyvariants. As each transmitter can have a unique address allocated to itby a receiver during the pairing phase, it is possible to make theinstallation secure using a rolling code method. In this case, the table26 of the receiver contains, for a transmitter, at least two fields:

-   -   an address field containing a fixed identifier transmitted to        the transmitter during the pairing phase and then accepted by        the receiver as the address for that transmitter;    -   a field CR containing an initial rolling code value.

The initial value of the rolling code is also transmitted to thetransmitter during a pairing procedure; it can then be incremented eachtime the said transmitter is operated, according to means of rollingcode management known to a person skilled in the art. In other words, inthe transmitter the address or the value of the rolling code—which canbe considered as a part of a generalised address—can be modifiedaccording to a predetermined algorithm after the sending of a command;similarly, in the receiver the address or the rolling code valuecorresponding to a transmitter can be modified according to apredetermined algorithm after reception of a valid command from thattransmitter.

It is also possible to provide a third validation field in the table,for example a single bit field. This field can on the one hand be usedfor indicating that the corresponding address has been the subject of apairing operation and therefore that it must be recognized as valid. Inpairing mode, this field makes it possible to scan the table rapidly inorder to find an address for a transmitter to be paired; in operationalmode, the field makes it possible to scan the table rapidly in order toread the addresses recognized as being valid and to compare them with areceived address.

The content of the table 26—or at least of the address and rolling codefields—can be fixed in the factory. It is also possible to makeprovision for this content to be modifiable using a hardware or softwaremodule allowing the generation of pseudo-random numbers in the table. Ahardware solution can consist in using traditional contacts of“DIP-switches” type; a software solution consists in using apseudo-random number generator.

This solution provides an important benefit in terms of independence ofthe owner of the installation with respect to the hardware manufacturer.It is then possible for the owner of the installation himself to definea set of codes which has not been fixed in advance by the manufactureror by the installer. This solution is also particularly advantageous inoperation according to the second principle: only the receiver containsthe hardware or software module allowing the generation of numbers; thetransmitters do not need to contain this module. Conversely, ageneration of numbers in an installation according to the firstprinciple necessitates providing each transmitter with a module, forexample of the DIP-switches type.

Therefore, by using the second principle and such a module, thefollowing drawbacks are avoided:

-   -   nothing is less obvious than generating a truly random number by        calculation: simple algorithms are often biased by the physical        characteristics of the components that will preferably choose to        switch to a “1” state rather than a “0” state, or vice-versa.        There are algorithms making it possible to generate binary        sequences that are pseudo-random to a high degree, but the fact        of installing such an algorithm in each one of the transmitters        represents a costly increase in computing power and in the        memory size in each transmitter, whereas the latter are portable        and necessitate the highest degree of miniaturization or the        lowest consumption and the lowest cost; conversely, the receiver        already has a large memory capacity and a larger computing power        and is not subject to consumption restrictions; is can more        easily receive such an algorithm;    -   in the case in which each transmitter according to the first        principle would have the ability to modify the identifier in a        random manner, the problem arises in that it is possible for two        transmitters of the same installation to take the same        identifier at the time of configuration. If this occurs, in the        case of rolling code, the problem already mentioned arises again        in that the receiver will be incapable of following the RC        assigned to each transmitter: one of them will be rejected by        the receiver.

In this embodiment combining the second principle and a generation ofnumbers, the invention therefore makes it possible to provide a higherlevel of security and reliability than in the prior art bysimultaneously combining: the advantages of the rolling code and theadvantages of random configuration at the owner's initiative, this beingin a multi-transmitter configuration.

The module can be activated automatically when the receiver is firstswitched on, or it can be used during each pairing operation in order togenerate a new address. This module can be activated by means of aspecific button, or of a particular control code transmitted by aparticular transmitter. If the entire table is regenerated, it isessential to carry out a new pairing of the transmitters in order toprovide them with valid addresses. In the case of such a module, it isappropriate that the algorithm used should guarantee that two identicalvalues in the table are impossible, unless it is accepted that twotransmitters receive the same address.

As a variant, it is possible that the modification applies only to aparticular position in the table, corresponding for example to atransmitter indicated as being lost or stolen. In this case, thereceiver 4 can be provided with means—keyboard, display or othermeans—making it possible to locate a particular zone in the addresstable. This variant makes it possible in particular, in the case of lossor theft of a transmitter, simply to delete the corresponding address inthe address table; it thus becomes impossible to use the transmitter forcontrolling the receiver. The corresponding line in the table can thenbe used for another transmitter.

The invention also provides another operational mode which considerablysimplifies the architecture of the receiver 4. In this embodiment, theactivation of the pairing means 28 of the receiver systematically causesthe generation of a random value replacing in the table the value wouldnormally have been sent to the transmitter, or adding a new randomlygenerated number to the table. This embodiment has the advantage ofsecurity—since a new random value is generated for each new pairedtransmitter; it thus has the advantage of simplicity; it is notnecessary to provide a hardware or software command to activate thepseudo-random numbers generating module.

As is known in the prior art, and as the assignee produces in the radioremote control products marketed under the RTS label, the command toswitch to learning or pairing mode can come from a transmitter alreadyhaving a means of identification by the receiver 4 as it is alreadypreviously paired. External access to the pairing means 28 is nottherefore essential provided that an already paired transmitter isavailable. In order to pair a new transmitter, it suffices to use atransmitter that is already paired, on the basis of which the nextpairing will be carried out.

This embodiment can be combined with the preceding ones, as shown by thefollowing example. Let it be assumed that the transmitter T3 of aninstallation comprising four transmitters has disappeared. Using itstransmitter T2 for example, the owner generates a combination of keyswhich makes it possible to inform the receiver 4 that the “pairing byreplacement” mode must be activated. In this pairing mode, the table isnot scanned until an address not yet used is found, but the rank of theaddress to be replaced in sent by the owner to the receiver 4 using atransmitter; it is preferably possible to use the already authenticatedone, or the one that is to be paired. For example, it is possible totransmit to the receiver the rank of the address to be replaced in theform of a succession of key pressings, the number of pressingsindicating the rank.

It is also possible to use a reaction of the owner, by means of histransmitter, to the signal transmitted by the receiver 4 using anindicator lamp or even using the actuator controlled by the operatingunit. Thus the receiver 4, which can contain four valid addresses willsuccessively flash an indicator lamp once, then twice, three times andfour times, each time leaving a time interval (for example of 3 seconds)sufficient to allow the owner to validate the choice, for example byreiterating the pairing command. This validation will therefore becarried out in the chosen example when there is a triple flashing, orwhen there is a triple movement of the actuator.

The address contained in the table and previously corresponding to thetransmitter T3 in the example is then deleted. The corresponding line inthe table is used for storing a new address, which is transmitted to anew transmitter during a pairing phase; for this purpose it is possibleto use a randomly generated address, as explained above.

In all cases, the addresses can have a common part and a variable part,whether it is generated randomly or not. The common part can for examplebe a function of the serial number of the receiver, the family code ofthe receiver, the transmission mode used, or something else. Thisembodiment makes it possible to provide the transmitter, during thepairing phase, with information on the receiver. Furthermore, thisembodiment can make it possible to limit the risk of two receiverssupplying the same address to different transmitters. It is thereforepossible to use identical transmitters for different types of receivers,the address informing the transmitter which type of receiver it issending a command to; this embodiment is particularly advantageous foruniversal transmitters, or for transmitters having several memories andable to send commands to several different receivers. The transmittercan also in this case adapt the meaning of the keys according to thereceiver.

The invention is not of course limited to the embodiments describedabove. Thus, in the examples, the case considered was where there wasone receiver and a plurality of transmitters; but the invention alsoapplies to several receivers and several transmitters, each receivercommunicating an address or identifier to each transmitter during thepairing phase. In the different embodiments, the addresses transmittedto each transmitter by a receiver are different; this allows increasedsecurity in particular, as mentioned above; even though this is notconsidered as advantageous, it is however also possible to allow areceiver to transmit a same address to two different transmitters: therewould then be two undifferentiated transmitters among the varioustransmitters paired with the receiver.

The transmission methods used between a transmitter and a receiver aregiven only by way of example and can be modified. The invention applies,in particular, whether the transmitters and receivers use a singlefrequency or whether each one transmits on a separate frequency, or infrequency steps or with different modulations. In fact, the methodapplies since the receiver supplies the transmitters with an addressallowing them to be identified—irrespective of the manner in which thisidentification is carried out.

The words “receivers” and “operating units” have been used, which applyin particular to the example of rolling shutter operating units. Thereceiver and the operating unit can be separate elements, as in theexamples, or can form a single assembly.

In the examples, the transmitters send their address to the receiverduring the transmission of a command; it is obviously possible to encodeor encrypt the corresponding address using techniques known in the priorart.

1-10. (cancelled)
 11. A method of pairing a receiver with at least twotransmitters, comprising the steps of: a) the supply of an address bythe receiver to a first transmitter, and storage of the supplied addressby the receiver; b) storage of the address by the first transmitter; c)supply by the receiver to a second transmitter of an address differentfrom the address supplied to the first transmitter, and storage by thereceiver of the supplied address; and d) storage by the secondtransmitter of the address supplied by the receiver; each transmitterbeing able to transmit to the receiver a command, that is a function ofthe stored address, the receiver executing the command only if theaddress of which it is a function is an address stored in the receiver.12. The method according to claim 11, wherein the supply step comprisesthe generation of the address by a pseudo-random generator.
 13. Themethod according to claim 11, comprising for a transmitter, themodification according to a predetermined algorithm of the storedaddress or of a part of the latter after the sending of a command to thereceiver.
 14. The method according to claim 12, comprising for atransmitter, the modification according to a predetermined algorithm ofthe stored address or of a part of the latter after the sending of acommand to the receiver.
 15. The method according to claim 11 furthercomprising, for the receiver, the modification according to apredetermined algorithm of the stored address, or of a part of thelatter, for a transmitter after receipt of a command from thattransmitter.
 16. The method according to claim 11, wherein it comprisesa step of deletion by the receiver of the address supplied to atransmitter.
 17. A non-paired receiver, comprising command receivingmeans, a table containing at least two separate addresses and a circuitcapable of extracting an address from a command received by thereceiving means and of comparing an extracted address with the addressesin the table.
 18. The receiver according to claim 17, wherein itcomprises a means of transmitting an address from the table.
 19. Thereceiver according to claim 17, wherein the table contains, for anaddress, an associated rolling code value.
 20. The receiver according toclaim 18, wherein the table contains, for an address, an associatedrolling code value.
 21. The receiver according to claim 20 wherein thetable contains, for an address, a field representing the transmission ofthat address.
 22. An installation comprising a non-paired receiver,comprising command receiving means, a table containing at least twoseparate addresses and a circuit capable of extracting an address from acommand received by the receiving means and of comparing an extractedaddress with the addresses in the table, and at least two transmitters.